The invention relates generally to a medical device, and more particularly to an medicament delivery device for automatically injecting a medicament into a body of a patient.
Exposure to certain substances, such as, for example, peanuts, shellfish, bee venom, certain drugs, toxins, and the like, can cause allergic reactions in some individuals. Such allergic reactions can, at times, lead to anaphylactic shock, which can cause a sharp drop in blood pressure, hives, and/or severe airway constriction. Accordingly, responding rapidly to mitigate the effects from such exposures can prevent injury and/or death. For example, in certain situations, an injection of epinephrine (i.e., adrenaline) can provide substantial and/or complete relief from the allergic reaction. In other situations, for example, an injection of an antidote to a toxin can greatly reduce and/or eliminate the harm potentially caused by the exposure.
Because emergency medical facilities may not available when an individual is suffering from an allergic reaction, some individuals carry an auto-injector to rapidly self-administer a medicament in response to an allergic reaction. Some known auto-injectors are cylindrical in shape and include a spring loaded needle to automatically penetrate the user's skin and inject the medicament. Such known auto-injectors can be bulky and conspicuous, which can make carrying them inconvenient and undesirable. Moreover, some known auto-injectors do not have a retractable needle and, as such, cause a sharps hazard when injection is complete.
Some known auto-injectors include a locking cap at the proximal end of the auto-injector to prevent inadvertent actuation and a needle cover at the distal end of the auto-injector. Such a configuration can, at times, cause a user to become confused as to which end of the auto-injector is the “needle end” (i.e., the distal end) and which end of the auto-injector is the “actuation end” (i.e., the proximal end). As such, in some situations, a user may mistakenly actuate the known auto-injector away from the intended injection site. Such an error can result, for example, in the auto-injector being actuated into the user's thumb and/or finger.
Thus, a need exists for an auto-injector that can be more conveniently carried by a user and does not present a sharps hazard upon completion of the injection. Furthermore, a need exists for an auto-injector that can be actuated from its distal end.